changeset 42234:c4a50e863ee2

histedit: Speed up scrolling in patch view mode

Store patchcontents into the mode state, avoiding the expensive
call to ui for computing the patchcontents.

Before this change in large repos histedit patch view mode can
be very irresponsive.

--- a/hgext/histedit.py	Thu May 02 16:43:34 2019 -0700
+++ b/hgext/histedit.py	Thu Apr 25 15:30:40 2019 -0700
@@ -1079,6 +1079,8 @@
 def changemode(state, mode):
     curmode, _ = state['mode']
     state['mode'] = (mode, curmode)
+    if mode == MODE_PATCH:
+        state['modes'][MODE_PATCH]['patchcontents'] = patchcontents(state)
 
 def makeselection(state, pos):
     state['selected'] = pos
@@ -1134,7 +1136,7 @@
     if mode != MODE_PATCH:
         return
     mode_state = state['modes'][mode]
-    num_lines = len(patchcontents(state))
+    num_lines = len(mode_state['patchcontents'])
     page_height = state['page_height']
     unit = page_height if unit == 'page' else 1
     num_pages = 1 + (num_lines - 1) / page_height
@@ -1394,7 +1396,8 @@
 
     def renderpatch(win, state):
         start = state['modes'][MODE_PATCH]['line_offset']
-        renderstring(win, state, patchcontents(state)[start:], diffcolors=True)
+        content = state['modes'][MODE_PATCH]['patchcontents']
+        renderstring(win, state, content[start:], diffcolors=True)
 
     def layout(mode):
         maxy, maxx = stdscr.getmaxyx()